Ignition apparatus for internal combustion engines



Sept. 16, 1941. F. R. F. RAMSAY IGNITION APPARATUS FOR INTERNALCOMBUSTION ENGINES Filed March 30, 1940 m P, E W

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Patented Sept. 16, 1941 IGNITION APPARATUS FOR INTERNAL COM- BUSTIONENGINES Frank Raymond Faber Ramsay, London, England, assignor to D.Napier & Son Limited, London, England, a company of Great BritainApplication March 30, 1940, Serial No. 326,992

In Great Britain April 13, 1939 v 9 Claims. This invention relates toenergising apparatus for supplying low tension current impulses to theprimary winding of a high tension magneto of an internal combustionengine to facilitate starting.

For this purpose it has been proposed to provide a primary circuitcomprising a battery and an interrupter of the buzzer type with switchesfor closing the primary circuit and connecting it to the primary windingof the magneto during starting. It is convenient to construct theenergising apparatus and the switches controlling it as a unit and inprior proposals this has meant in practice that this apparatus must bearranged near the pilot or other person responsible for the control ofthe engine. This is, however, not always either convenient or desirableand the object of the present invention is to provide an improvedarrangement which may be applied to the previously proposed apparatusreferred to above, or to other apparatus of the kind referred to, forexample the apparatus forming the subject of the present applicantscopending United States of America Patent application Serial No.269,256, which will enable the energising apparatus to be disposed at adistance from the point of control, for example near the engine ormagneto. To this end in energising apparatus of the kind referred to forsupplying low tension current impulses to the primary winding of a hightension magneto of an internal combustion engine according to thepresent invention, there is combined with a primary circuit including aninterrupter and adapted to be connected to a source of current, anelectromagnetically operated switch which controls the connectionbetween the energising apparatus and the primary winding of the magnetoand is adapted to close automatically when the primary circuit isenergised and to open automatically when this circuit is deenergised.

Thus, a switch for closing the primary circuit may be provided adjacentto the point of control, while the energising apparatus itself,including the switch for connecting it to and disconnecting it from theprimary winding of the magneto, may be disposed at any desired point. I

Where, as will generally be the case, an interrupter of the buzzer typeis employed, the electromagnetically operated switch may be actuated bythe stray-field from the coil of the buzzer. Thus, for example, theinterrupting contacts of the buzzer may lie at one end of the core ofthe lies at the other end thereof. In this case the coil convenientlyhas an open-ended core with a strip of metal constituting a magneticlink extending between but separated by gaps from the ends of the corefor the purpose of concentrating the stray field.

In any case, the movable contact of the electromagnetically operatedswitch is conveniently of such weight that when the coil is energised itwill maintain the eelctromagnetically operated switch permanently closedin spite of the interrupted nature of the current flowing through theprimary circuit. For example, the electromagnetically operated switchmay comprise a comparatively heavy armature mounted upon a metal leafwhich carries, preferably resiliently, two contacts insulated from oneanother and adapted to engage two fixed contacts, when the coil isenergised so as to connect the energising apparatus to the primarywindings of two magnetos.

In such a case the armature is preferably connected to the metal leaf insuch a manner that it can rock relatively to the leaf to a suflicientextent to enable the armature to bed properly upon the end of the coreof the coil without materially distorting the leaf. Thus the armaturemay be connected to the leaf at a single point, in which case thearmature can rock relatively to the leaf in all directions withoutmaterially distorting it or may be connected to the leaf so that it canrock relatively thereto only in one direction, e. g. about a line atright angles to the length of the leaf. In this way, buzzing of thearmature due to its not bedding down properly on the core with theresult that the armature tends to rock about the point at which itengages the core and thus to distort the leaf, tends to be prevented.

The invention may be applied to apparatus for use with a single magnetoor for use with two magnetos associated with a single engine and twoarrangements according to the invention as applicable to two magnetosare illustrated diagrammatically by way of example in the accompanyingdrawing, in which Figure 1 shows one arrangement as applied to twomagnetos of an engine in which the magnetos supply alternate sparks,

Figure 2 shows an arrangement as applied to two magnetos of an engine inwhich the magnetos supply simultaneously sparks,

Figure 3 is a somewhat diagrammatic side elevatior of a combinedinterrupter and electromagnetically controlled switch of the kindemployed in the construction shown in Figure 2, and

coil while the electromagnetically operated switch Figure 4 is adiagrammatic plan of the construction of switch diagrammatically shownin Figure 3.

In the construction diagrammatically shown ondary winding D of atransformer D. The primary winding D of the transformer D is arranged ina primary circuit D including a battery E and an interrupter F of thebuzzer type operated by the stray field from the transformer D, thiscircuit being controlled-by a manually operated switch G.

Arranged in parallel with the primary winding D is the operating coil Cof the switch 0 which when energised is arranged to close the switch.

The operation of the apparatus is as follows. When the switch G isclosed the coil C and the primary winding D are energised. Theinterrupter F thus comes into operation and simultaneously the switch Cis closed to connect the two magneto primary windings A and B to thesecondary winding D of the transformer D. Since the two magnetos A and Bsupply alternate sparks the contact-breaker of one magneto is alwaysclosed when that of the other opens. The closed contact-breaker thusearths one end of the secondary winding D and thus completes the circuitthrough this winding and the primary winding of the other magneto. Inthis way as long as the switch G is kept closed a series of low tensioncurrent impulses are delivered to the primary winding of whichever ofthe two magn'etos at any moment has its contact-breaker open. When theengine has been started, the switch G is released, whereupon the switch0 opens to break communication between the magnetos and the energisingapparatus.

It will be seen that the energlsing apparatus (constituted by theapparatus enclosed in a dotted line) 1 can be arranged and constructedas a unit which can then be coupled to the battery E and switch G by apair of conductors and to the magnetos by a further pair of conductors.Further these latter conductors may be the same as the normal earthim;conductors leading to the usual ignition switch.

In the alternative construction illustrated in Figure 2 the magnetos Aand B are of the same conventional type as shown in Figure 1 but areadapted to supply simultaneous sparks. To this end the conductors A, Bare adapted to be connected through switch apparatus H respectively toopposite ends of the secondary winding J of a transformer J, the centreof this winding being earthed as shown. In this construction, as intheconstruction shown in Figure 1, the primary winding of thetransformer J is arranged in a primary" circuit including abattery K andan interrupter K of the buzzer type operated by the stray field from thetransformer, the primary circuit being controlled by a manually operatedswitch L.

Inlthis arrangement the switch H'for coupling the secondary winding J tothe magnetos A and secure'by Letters Patent is:

B is also arranged to be operated by the stray field from thetransformer J. To this end the switch H comprises a spring leaf Manchored at M and carrying at M an armature of such weight that whendrawn into contact with the end of the core of the transformer J it willremain in contact therewith in spite of the intermittent nature of thecurrent caused by the interrupter K as shown connected to the leaf M ata single point so that it can rock to a small degree without materiallydistorting the leaf and can thus readily bed down on the end of thetransformer core. Also carried by the leaf M but insulated therefrom aretwo contacts M, M connected by flexible leads M respectively to theconductors A and B" and adapted when the transformer J is energised toengage contacts M, M connected respectively to opposite ends of thewinding J Also arranged in the circuit of the battery K and arranged tobe closed by the switch L is the operating coil of an electromagnetic.switch 0 arranged to bring an electric engine starter into operation.

The operation of the apparatus shown in Figure 2 is as follows. When theswitch L is closed the primary windingof the transformer J is enrgised,the interrupter K comes into operation, the switch H is closed and hencea series of low tension current impulses are transmitted through theconductors A and B from the secondary winding J to the primary magnetowindings. At the same time th switch 0 is closed to bring the electricstarter into operation and hence cause rotation of the enginecrankshaft. Starting of the engine is thus effected whereupon the'switch L is opened and the engine continues to operate in the normalway.

In this construction also it will be seen that only two leads arerequired to the energising apparatus (enclosed in a dotted line) fromthe battery and switch L and only two leads from this apparatus to themagnetos.

Figures 3 and 4 show still somewhat diagram- 1 matically how thecombined transformer J, interrupter K and switch H may be constructed.Thus it may comprise a. casing -P in which the transformer proper isdisposed with the ends J, J of the transformer core projecting fromopposite ends of this casing. Disposed adjacent to the end J of the coreis a spring-mounted interrupter armature K" carrying a contact Knormally making contact witha contact K on a spring leaf K the contactsK K3 thus constituting an interrupter of the buzzer type in the circuitof the primary winding of the transformer. 7 Disposed adjacent to theend J of the core is the armature M supported on the spring leaf M. Inthis construction howevenli'nstead of the contacts M, M being directlycarried by the leaf M they are carried by separate leaves M M arrangedto be acted upon by a stripof insulating material M secured to the leafM. Actually the opposite ends of theswinding J 'shown dotted in the lefthalf of Figure 3, are

connected as shown in Figure 2 respectively to two contacts M', Marranged one behind the other in this figure and arranged to makecontact respectively with the contacts M- and M as in Figure 2, aspreviously described. 7

What I claim as my invention and desire to 1. Energising apparatus forsupplying low tension current impulses to the primary winding ofa hightension magneto of an internal combus- In order to assist this thearmature M is tion engine, comprising a primary circuit including aninterrupter and adapted to be connected to a source of current, and anelectromagnetically operated switch for controlling the connectionbetween the energising apparatus and the primary winding of the magnetoarranged to close and open automatically as the primary circuit isrespectively energised and deenergised.

2. Energising apparatus for supplying low tension current impulses tothe primary winding of a high tension magneto of an internal combustionengine, comprising a primary circuit includingan interrupter of thebuzzer type arranged to be connected to a source of current, anelectromagnetically operated switch for controlling the connectionbetween the energising apparatus and the primary winding of the magnetoarranged to close and open'automatically as the primary circuit isrespectively connected to and disconnected from the source of current.

3. Energising apparatus as claimed in claim 2, in which theelectromagnetically operated switch is actuated by the stray field fromthe coil of the interrupter.

4. Energising apparatus as claimed in claim 2, in which the interruptingcontacts constituting the buzzer lie at one end of the core of the coilwhile the contacts of the electromagnetically operated switch lie at theother end thereof.

5. Energising apparatus as claimed in claim 2, in which the primarycircuit includes the primary winding of a transformer, the secondarywinding of which is arranged to be connected to the primary winding ofthe magneto by the electromagnetically operated switch.

6. Energising apparatus as claimed in claim 2, in which the interrupteris operated by the stray field from a transformer the primary winding01' which lies in the primary circuit while the secondary winding isarranged to be connected to the primary winding of the magneto by theelectromagnetically operated switch.

7. Energising apparatus as claimed in claim 2, in which theelectromagnetically operated switch comprises an armature arranged to bedrawn into contact with a core when the latter is magnetisedelectrically and of such weight as to remain in contact therewith aslong as the primary circuit is connected to the source of current inspite of the interrupted nature of the current in that circuit.

8. Energising apparatus as claimed in claim 2, in which an armature isoperated by said switch and is carried by a spring leaf whereby theswitch contacts are directly or indirectly moved.

9. Energising apparatus as claimed in claim 2, in which an armature isoperated by said switch and is mounted on a spring leaf so as to becapable of limited rocking movement relatively thereto withoutmaterially distorting the leaf so as to iacilitate the bedding of thearmature on the core.

FRANK RAYMOND FABER RAMSAY.

